1. Field of the Invention
This invention relates to a pneumatic tire and a method of making the same.
2. Prior Art
Research and development efforts in the automobile industry have been of late directed more to reducing fuel consumption, inter alia, and such efforts are focussed among other technological approaches on the production of light weight pneumatic tires.
Standard pneumatic automobile tires are interiorly lined with a gas-impermeable layer such as butyl rubber. However, because, butyl rubber does not adhesively bond well with other rubber materials, it is necessary to resort to a tie gum or other suitable adhesive sheet applied intermediate between a butyl rubber liner and a rubber-coated carcass layer in a tire structure. Furthermore, butyl rubber per se is not completely impermeable and therefore its liner thickness must be increased at least to the order of several hundred .mu.M to be able to maintain a requisite air pressure in the tire. Thus, the thickness of a butyl rubber liner together with the thickness of an intermediate adhesive layer of tie gum or the like adds up to a total thickness exceeding 1 mm (1,000 .mu.M) which in turn contributes to increased weight of the tire.